the races to watch include massachusetts where polls show republican incumbent scott brown in a close race with democrat elizabeth warren. in missouri, democratic incumbent claire mccaskill faces a tough challenge from republican richard mourdock despite his controversial comments about rape. in all, 33 senate seats are up for grabs with races in several states that can go either way. >>> closer to home now it's less than an hour before the polls open up here in california. but many people have already voted. cbs 5 reporter cate caugiran is at the alameda county registrar's office with more. >> reporter: we spoke with the registrar of voters just half hour ago, who says they have been ready. they actually came here about 5:00 this morning. normally 26 people work in the office but they are adding about 200 more to deal with possible crowds today. as you mentioned polls will open in about less than an hour. but thousands or hundreds of thousands of bay area voters have already turned in their ballots. here at the alameda county courthouse, the registrar says they saw thousands of early